Many studies have reported the effect of hypertension on microcirculation of the retina. Advance of optical coherence tomography angiography (OCTA) allows us more detailed observations of microcirculation of the retina. Therefore, we compared OCTA parameters between chronic hypertension (disease duration of at least 10 yrs; Group A, 45 eyes), relieved hypertensive retinopathy (grade IV HTNR < 1 yr prior; Group B, 40 eyes), and normal controls [Group C (50 eyes) ≥ 50 yrs old and Group D (50 eyes) < 50 yrs old]. A 3 × 3 mm macular scan was performed in each group by OCTA. In vessel density of 3 mm full, group A and B were significantly decreased compared to normal control group (Group A vs. C; 19.4 mm⁻¹vs. 20.1 mm⁻¹, Group B vs. D; 19.8 mm⁻¹vs. 21.8 mm⁻¹, all p < 0.05). In foveal avascular zone, group A and B were significantly increased compared to normal control group (Group A vs. C; 0.35 mm²vs. 0.30 mm², Group B vs. D; 0.36 mm²vs. 0.29 mm², all p < 0.05). OCTA is useful for examining retinal microcirculatory changes in hypertension and we confirmed that hypertension affects the OCTA parameters. Considering the effect of hypertension on the change of microvasculature, care is required in the interpretation of OCTA parameters in various ophthalmic condition.

The quality of the scan image is important in microvascular circulation analysis using optical coherence tomography (OCTA). We aimed to investigate the effect of signal strength (SS) on OCTA metrics and minimum SS level that could be considered optimal. Macular 6 × 6 mm angiography images were acquired, and all subjects were divided into four groups according to the SS (SS 7, SS 8, SS 9, and SS 10) of the OCTA image. Vessel density (VD), perfusion density (PD), and foveal avascular zone (FAZ) metrics of the superficial capillary plexus were compared. In total, 446 eyes from young healthy subjects were included. As the SS increased from 7 to 10, the VD and PD of the total area, and the FAZ area increased significantly (all, p < 0.001), but there were no significant difference between SS 9 and SS 10 in all metrics. Correlation analysis between the SS and each parameter showed a high correlation coefficient (VD, r = 0.668; PD, r = 0.671; FAZ area, r = 0.570; all, p < 0.001). The measurements of VD, PD, and FAZ using OCTA varied significantly with the SS, and at least 9 of SS is recommended. The physician should be careful in the analyses of OCTA measurements showing different values of the SS.

To investigate the difference in the occurrence of postoperative epiretinal membranes (ERMs) in vitrectomy for rhegmatogenous retinal detachment with and without peeling of the internal limiting membrane (ILM). The medical records of the 135 patients, who underwent vitrectomy for primary rhegmatogenous retinal detachment from November 2007 to August 2011, were analyzed retrospectively. Of the subjects, 70 patients underwent ILM peeling during the surgery and 65 did not. The best-corrected visual acuity, fundus photograph, and optical coherence tomography were collected 3, 6, and 12 months postoperatively. The relationship between ILM peeling and the preoperative findings of rhegmatogenous retinal detachment and development of a postoperative ERM was analyzed. No ERM occurred in the ILM peeling group, whereas an ERM occurred in 14 of 65 patients who underwent vitrectomy without ILM peeling (21.5%). This difference was significant (P < 0.001). The occurrence of a postoperative ERM was not significantly correlated with other preoperative factors. In the macular-on group, the overall mean best-corrected visual acuity was better in the ILM peeling group and was significantly higher 12 months postoperatively (P = 0.03). Internal limiting membrane peeling seems to prevent the occurrence of a postoperative ERM in patients with primary rhegmatogenous retinal detachment.

Aim To determine the longitudinal changes in the axial length (AL) in patients with high myopia without any other ophthalmic disease Methods Participants were divided into two groups: a high myopia group (60 eyes) without myopic degeneration, such as chorioretinal atrophy or posterior staphyloma, and a control group (60 eyes). Both groups were further divided into subgroups according to the AL: subgroup 1 (≥27.5 mm), subgroup 2 (26.0–27.5 mm), subgroup 3 (24.5–26.0 mm) and subgroup 4 (<24.5 mm). The ALs were measured five times at 1-year interval using an IOL master, and the AL was fitted with linear mixed models. Results In the high myopia group, the AL showed a relatively constant increase at each visit, and they were significantly different with previous measurements at most visits, whereas the control group showed no significant change of AL. Subgroups 1,2 and 3 showed significant changes in AL over time (0.064, 0.032 and 0.012 mm/y, respectively). In univariate analyses, age, best-corrected visual acuity, baseline AL and anterior chamber depth were significantly correlated with changes in the AL in the high myopia group. In multivariate analysis, only baseline AL remained significant (p<0.001). Conclusions Myopic eyes, including moderately myopic eyes, showed a consistent increase in AL over 4 years, and eyes with a longer baseline AL showed a greater increase in AL than eyes with a shorter AL.